Précising mechanisms are used in high speed electronic component testing machines for aligning electronic components for testing and/or further processing. Typically, electronic components are fed to a high-speed electronic component testing machine by using a vibration bowl feeder or other conveying means. The electronic components are then separated and picked individually by a pick-head to be transferred for further downstream testing and/or processing.
In the interests of increasing processing speed, the electronic components are fed in bulk and they may be in various orientations when they are fed to the pick-head. Thus, the orientations of these separated electronic components will not be the same when they are picked up.
A précising mechanism is therefore required to correct a position of an electronic component before it is transferred to other testing or processing stations. A mechanism to adjust the electronic component is usually incorporated at the précising station, or it may be included as a separate module, in order to re-align the electronic component to the required orientation.
One type of précising mechanism comprises a plurality of jaws which are arranged at a specific orientation. This specific orientation coincides with the required orientation of the electronic components, and the said orientation of the plurality of jaws is fixed regardless of the initial orientation of the electronic component when it is fed into the précising station. Conventionally, the jaws of the précising mechanism may be positioned at four sides of the electronic components or at two corners thereof to cooperate to push the electronic components to their required orientations. After the pick-head places an electronic component onto the précising mechanism, the jaws of the précising mechanism will push the electronic component to force it to align to its required orientation.
FIG. 1 illustrates a first method of précising an electronic component according to the prior art. (i) An electronic component 10 is picked up in an unaligned orientation. (ii) The electronic component 10 is then placed on a platform 12 of a précising mechanism in the unaligned orientation. (iii) A plurality of jaws 14 of the précising mechanism will close and press onto the corners of the electronic component 10 and then the side walls thereof. When the jaws 14 close totally, the electronic component 10 is aligned in the required orientation. (iv) Once the electronic component 10 has been aligned in the required orientation, the jaws 14 will open and the aligned electronic component 10 may be picked up by a pick-head.
FIG. 2 illustrates a second method of précising an electronic component according to the prior art. The main difference between this method and the first method is that the précising mechanism comprises a pair of jaws 16 that are L-shaped. (i) An electronic component 10 is picked up in an unaligned orientation. (ii) The electronic component 10 is then placed on a platform 12 of a précising mechanism in the unaligned orientation. (iii) The jaws 16 of the précising mechanism will close and press onto the corners of the electronic component 10 and then the side walls thereof. When the jaws 16 close totally, the electronic component 10 is aligned in the required orientation. (iv) Once the electronic component 10 has been aligned in the required orientation, the jaws 16 will open and the aligned electronic component 10 may be picked up by a pick-head.
A shortcoming that is faced with these designs of the précising mechanism is that they risk damage to electronic components if the initial orientations of the electronic components deviate too much from their required orientation.
Japanese patent publication number JP2009-026936 entitled “Positioning Device” provides a positioning device which prevents a shock caused by the catching of a guide during positioning of an electronic component. It describes guide mechanisms comprising pawls which abut against side surfaces of the electronic component and guide the electronic component from four directions to correct its orientation. The guide mechanisms are configured to be opened and closed by cam plates. However, although this approach may somewhat reduce damaging the corners of the electronic component, it requires many motion steps, which increases cycle time and reduces throughput.
It would thus be beneficial to implement an efficient approach to safely align electronic components which does not employ purely mechanical means requiring many motion steps.